The fourth among the Dasavatara is Sri Nrisimha-avatara. Among the innumerable avataras, twenty-five are pre-eminent as has been stated before in connection with Matsya-avatara. Of these twenty-five, Sri Nrisimhadeva is the fourteenth. He is the vaibhava-vilasa (expansion in magnificence) of the tadekatma form of Sri Krishna.
The second catur-vyuha (quadruple expansion) of Sri Krishna is comprised of Vasudeva, Sankarshana, Pradyumna and Aniruddha, and each of these has two further vilasa expansions. Pradyumna’s expansions are Sri Nrisimhadeva and Sri Janardana. Besides that, it is also described that in the second catur-vyuha, Vasudeva, Sankarshana, Pradyumna and Aniruddha are the prabhava-vilasa (predominating transcendental pastime expansions) of Sri Krishna. There are a total of twenty further expansions of these four prabhava-vilasa forms. They can be recognised according to the placement of four different symbols in Their hands: conch (sankha), mace (gada), lotus (padma) and disc (cakra). Regarding Sri Nrisimhadeva, these symbols appear in the order of cakra, padma, gada and sankha (disc in the lower right hand, lotus in the upper right hand, mace in the upper left hand and conch in the lower left hand).
In the Seventh Canto of Srimad-Bhagavatam, the pastime of Sri Nrisimhadeva’s appearance is briefly narrated as follows:
Due to the curse of the four Kumaras (Sanaka, Sanandana, Sanatana and Sanat), Jaya and Vijaya, the doorkeepers of Vaikuntha, took birth as Hiranyaksha and Hiranyakasipu, as the two sons of Diti and Kasyapa Åshi. Of the two sons, Hiranyakasipu was senior and affectionate to his brother. Lord Sri Hari, in the form of Lord Varaha, took the side of the demigods and killed Hiranyaksha. Desiring to take revenge, Hiranyakasipu began to consider Lord Vishnu as his enemy and developed malicious feelings toward Him. He encouraged the demons to disturb ritualistic ceremonies and kill the brahmanas. He also decided to perform severe austerities for one hundred years to get the benediction of achieving unrivalled supremacy of the three worlds. When Lord Brahma became pleased by his austerities and appeared before him, Hiranyakasipu asked for the benediction of becoming immortal. Lord Brahma explained his inability to give him the boon of immortality, so Hiranyakasipu asked for the boon of immortality in a different manner by requesting the following conditions: that he not be killed during the day or night, either inside or outside, in the sky or on the ground. He also asked that he not be killed by any weapon or by any living being created by Brahma. Thus, Hiranyakasipu became extremely powerful by the boon of Brahma and enslaved all the Lokapalas (presiding deities of the eight directions of the universe). He became the sole monarch of the three worlds and enjoyed worldly pleasures while occupying Mahendra Bhavana, the residence of Indra. The demigods suffered due to his cruel behaviour and took refuge of Sri Hari. Lord Hari then gave them confidence saying, “When Hiranyakasipu becomes jealous of his devotee-son Prahlada, he will be destroyed.”
Hiranyakasipu had four sons: Samhlada, Anuhlada, Hlada and Prahlada. Of these, Prahlada was the best due to his virtuous qualities. While in his mother’s womb he had heard and assimilated the teachings of Narada Muni. As he was always absorbed in meditation on the Supreme Lord, the peaceful and tranquil-hearted Prahlada could not perceive anything in this world unrelated to God, who is all-good.
As it was the custom in those days to send children to the guru’s home for education, Hiranyakasipu sent Prahlada, who was well versed in ethics, to Nanda and Amarka, the two sons of the demon-guru Sukracarya. Nanda and Amarka lived near the palace. They began to teach politics to Prahlada along with the other demon children. After hearing the teachings of his gurus, Prahlada would always give the expected reply, but in his heart he did not like these teachings. “This is my country, that is another’s country. This is our group, that is another’s group.” Politics is based upon the foundation of this division between “mine and thine.” There can be no politics without this “mine and thine” or “friend and foe” mentality. So, this is the demoniac mentality. Here, the noteworthy thing is that although the highly learned Prahlada understood the futility of the teachings of his teachers, he never behaved in a rude or disrespectful manner, but gave befitting respect to them. If a person respects his parents, teachers, elders, guardians and others senior to himself in age, he is benefited and there remains consistency in the social arrangement. Selfishness and disrespect of elders and seniors will bring disorder everywhere. Prahlada’s character is unique and his every conduct is worth following.
When Prahlada’s teachers Nanda and Amarka saw that Prahlada had attained a good education and was answering all their questions properly, they thought it wise to send him to his father, as he would be glad to see Prahlada’s educational progress. Hiranyakasipu was happy at the return of Prahlada from his guru’s home. He took him on his lap and cordially said, “My dear son Prahlada, tell me whatever you think to be saintly (sadhu).” By this, Hiranyakasipu meant that he wanted Prahlada to tell him some good words from whatever he remembered from his guru’s teachings that he could express without difficulty, as he was just a child.
Prahlada understood the intentions of his father, but as the question was put before Prahlada in the royal assembly, he thought that he ought to speak only the truth, which is actually saintly, otherwise the court members would misunderstand him. So he replied, “O emperor of demons, for the corporeal souls who are always perplexed due to the acceptance of perishable things and contact with non-eternal relations, I think it to be saintly to renounce the home which is like a dark well[1], the place of downfall, and to go to the forest to take refuge of and worship the lotus feet of Sri Hari.”
Hearing his son’s view on the worship of Vishnu, Hiranyakasipu smiled and thought that others must have spoiled the vulnerable intelligence of the child. He sternly ordered the demons to be careful in dealing with Prahlada and to take care lest any Vaishnava come in disguise and spoil his intelligence. After hearing about this order from Hiranyakasipu, Nanda and Amarka became worried. They knew that they had never taught Prahlada about Vishnu-worship, so he must have heard such things from some Vaishnava and spoken about it. If they tried to find out the name of that Vaishnava and tactfully inform the king about it, the king would not doubt them. With this intention, Nanda and Amarka addressed Prahlada in a very pleasing manner and said, “O joy of the demon dynasty, we bless you for the sake of your welfare. You should not tell a lie before your teachers. Speak the truth. We have not taught you about devotion to Vishnu. We have taught you with other demon children but their minds are not spoiled like yours. Did you speak for yourself in that manner, or has somebody spoiled your intelligence?” Prahlada understood the intentions of his teachers. So he first offered pranamas to the Supreme Lord who controls the maya potency that covers the intelligence of the living beings and creates the mentality of “mine and thine.” Then he said, “As iron is naturally attracted towards a magnet, my heart is similarly attracted towards the lotus feet of Cakrapani Sri Hari (Sri Hari, the holder of the disc weapon). Sri Hari has spoiled my intelligence.”
Prahlada’s reply was not what Nanda and Amarka wished to hear. They thought that Prahlada would mention someone’s name whom they could catch hold of, so they became angry and condemned Prahlada, “O ruiner of the family, defamer of the demon dynasty, you are like a thorn tree in the sandalwood forest which is the asura dynasty. Using you as an axe, Vishnu will destroy the sandal forest of the demons. Your intelligence is lost. There are four methods of politics, namely sama (conciliation), dana (monetary gratification), bheda (causing dissension) and danda (punishment), and your conscience will not be awakened without using the last method. Someone bring a cane immediately to flog this boy!” Thus, they tried to frighten Prahlada by striking a cane on the table; because Prahlada was the son of the emperor, they lacked the courage to actually beat him. They reproached him hastily but Prahlada remained silent. Again, they began to teach him the scriptures related to dharma, artha and kama (piety, wealth and the fulfilment of desires), and tried to educate him in politics.
After some time, Prahlada’s teachers saw that Prahlada had become expert in the four pillars of politics. He properly replied to every question. This time, they themselves would take him to the king. Thinking in this way, they first took Prahlada to see his mother. Prahlada made obeisances to his mother and she bathed him very affectionately and decorated him with various jewels. Then, Prahlada’s teachers took him to the royal assembly of King Hiranyakasipu, whereupon Prahlada made prostrated obeisances before his father. Seeing Prahlada, Hiranyakasipu felt great affection for him. He took him on his lap, embraced him, kissed him, and bathed him with tears of happiness. After this, Hiranyakasipu happily inquired, “O son Prahlada, you have taken instruction from your gurus for so long. Now, please tell me something excellent from their teachings.” Hiranyakasipu’s intention was that Prahlada should speak on what was best from the teachings of Ñanda and Amarka, considering them as gurus. But Prahlada was worried; he thought that if he replied according to his father’s wishes, the others present in the court would get the wrong impression about the teachings of a real guru. Ñanda and Amarka were not real gurus (sad-gurus) even though they were family gurus. A guru[2] should be srotriya[3] (well-versed in the sruti or Vedas) and have brahmanishtha (firm devotion to Brahman or God). Prahlada’s teachers were learned in sruti but lacked firm devotion to Brahman. They were only devoted to their specific mundane subjects or worldly knowledge, so their teaching was not the instruction of proper gurus. Prahlada decided to speak about the essence of all the lessons he had received from his real guru, Narada, who possessed the two qualities of srotriya and brahmanishtha, and replied:
“Dedicating oneself to Vishnu and following the nine forms of devotion, with the only object being the propitiation of Vishnu, is the highest form of genuine knowledge.” The nine forms of devotion are, respectively: sravanam (hearing), kirtanam (chanting), smaranam (remembrance of the name, form, attributes, personal associates and pastimes of the Lord), pada-sevanam (service of the lotus feet of the Lord. This also indicates service of the devotees of the Lord), arcanam (worship of the Deity), vandanam (offering prayers and obeisances), dasyam (service of God in the relationship of master and servant), sakhyam (service of God in friendship), and atma-nivedanam (total self-dedication to God).
Upon hearing Prahlada again speak about the worship of Vishnu, Hiranyakasipu thought that he must have learned this from Nanda and Amarka, the sons of his guru, Sukracarya. Thus, he became very angry and condemned them in a rude manner, “O lowest of brahmanas! O evil minded ones! What did you do? You disobeyed me; you adopted the favour of my enemy and taught my son Prahlada about worthless Vishnu-bhakti. A sinful person commits sin secretly but his sin manifests in the form of disease; similarly, a deceptive and wicked-minded person, although living in the form of a friend, ultimately discloses his real form through his deeds.” At this, the guru’s sons said, “O King, you have conquered Indra, and all the Lokapalas are afraid of you. We are but poor brahmanas. We would not dare to act against you. We have not taught Prahlada about devotion to Vishnu and neither has anyone else. Prahlada’s devotion to Vishnu is natural and inborn, so please restrain your anger.” In Satya-yuga, everyone spoke truthfully, so Hiranyakasipu believed his guru’s sons. He asked Prahlada, “O impolite one, O destroyer of the family, how have you become Krishna conscious if your gurus did not teach you in this manner?”
Prahlada replied, “Without the favour of a nishkincana maha-bhagavata (a perfect pure devotee, completely emancipated from worldly concerns), a grihavrata (a person engaged in household affairs) cannot become devoted to Sri Krishna either by himself or by the help of other grihavratas[4].” In other words, Prahlada’s devotion to Sri Krishna was not due to his own efforts or the help of the family guru’s sons. Rather, his devotion to Sri Krishna was due to the favour of nishkincana maha-bhagavata Sri Narada, the devotee of Sri Krishna. Upon hearing this undesirable statement from Prahlada, Hiranyakasipu became blind with rage and threw Prahlada from the throne with such force that any five-year-old child would have died at once, but the Lord saved him. Prahlada remained patient, steady and peaceful. He did not raise a even finger against his father or use any harsh words. Hiranyakasipu ordered the demons to kill Prahlada. At first, the demons did not wish to kill the king’s son, but when Hiranyakasipu repeatedly persuaded them to kill Prahlada by quoting different reasons and maxims, they began to attack the vital parts of Prahlada’s body with spears. As Prahlada’s mind was fully absorbed in and devoted to the indescribable Supreme Lord of the universe, all the efforts of the demons proved futile. Seeing this, Hiranyakasipu became even more suspicious and tried to kill Prahlada by various methods such as the celestial powerful elephant of the quarters, by serpents and by evil incantations. He tried to kill Prahlada by hurling him from a mountain, by burying him in a deep ditch, by poisoning him, by starvation, by exposure to severe cold and atmospheric pressure, by burning him in a fire and by stoning him. But when all efforts proved to be in vain, he began to think that the power of the child was immeasurable. Prahlada was not afraid of anything! Hiranyakasipu began to think that Prahlada was immortal, and worried that he himself might die if he opposed him. Thus, Hiranyakasipu sat down with his head hung low.
Seeing Hiranyakasipu dejected, Nanda and Amarka tried to console him by saying, “O King, you have conquered the three worlds single-handedly and all the Lokapalas are afraid of you. Therefore, you need not worry. Besides, one should not pay attention to the virtues and defects of a mere child.”
They suggested to him, “Until guru Sukracarya returns, Prahlada should be kept on an island so that he might not run away out of fear. Growing up with the acarya, serving the acarya and learning from the acarya will purify his intelligence.” Hiranyakasipu accepted the proposal of both the guru’s sons and told them to instruct the boy in the piety and charity suitable for a king. They carefully took Prahlada and the other demon children to an island. There, they began to teach him about dharma, artha and kama-material religiosity, economic development and sense gratification. One day, the teachers went to their homes to do some work. When the children came to know about their teacher’s departure, they thought it a good chance to play. Prahlada’s school friends called him out to play, but the highly learned Prahlada told them that he wished to say something to them, so they all changed their play-dress and gathered around Prahlada. Though all the children were of the same age as Prahlada, they had great respect and affection for him. Prahlada told the children about the duties of human beings: “The human birth is very rare and valuable because in such a birth one can realise the Supreme Lord. After realising Him, no material desires will remain. But this golden chance is not permanent because life is momentary. So, wise persons will follow bhagavata-dharma from their childhood and worship the Lord by hearing and chanting His glories. The thought that ‘I will perform devotional practices later on’ is not good. If the mind becomes attached to money, wife, son and relatives, then devotion will be difficult. If you do not devote yourself to the Lord’s worship now, many difficulties and problems will interfere with prayer later on.” Prahlada discussed all these things in detail, enabling the children to understand. In order to gain their confidence, he related to them everything about how he had received the message of Krishna-bhajana from Narada while in his mother’s womb. The demon children heard Prahlada’s teachings, and thinking them to be superior ideas, accepted them, thereby rejecting the teachings of their materialistic gurus.
Due to Prahlada’s influence, the minds of the demon children became fixed on the Supreme Lord. The anxious brahmanas Nanda and Amarka immediately went to the demon king to explain the situation. Hearing this implacable message, Hiranyakasipu became extremely angry. With harsh words, he condemned the young Prahlada who was standing politely with folded hands: “O impolite, dull-headed one! You are disobeying my rule. I shall send you to the abode of Yama right now. Even the Lokapalas are afraid of my anger. Why are you not afraid of me? Who has given you this strength?”
Prahlada replied, “Strength only comes from the one Supreme Lord, Sri Hari. Everyone gets their strength from Him. No one is our enemy except the uncontrolled mind. You should give up these demoniac thoughts of ‘friend and foe.’ In ancient times, foolish persons like you had the false pride that they had conquered the earth, but they could not even conquer the six passions residing in their own bodies. Those who have conquered the mind see no one as their enemy. Only the ignorant believe others to be their enemy.” By these words of Prahlada, Hiranyakasipu became more and more enraged and shouted, “O unintelligent fool! You condemn me and boast about conquering the six inherent cardinal passions of man. Certainly you want to die! You rascal, there is no Lord in the world other than me. If there is, then where is He?”
“Father, He is everywhere,” said Prahlada.
“Then why do I not see Him in this pillar?” retorted Hiranyakasipu.
“I see Him even in this pillar,” replied Prahlada.
The very powerful Hiranyakasipu condemned Prahlada with extreme anger and harsh words. “May your Lord save you!” Saying these words, he picked up his sword, rose from his throne and violently struck the pillar with his fist. As the pillar was struck, it emitted a terrible sound as if the whole universe was being shattered. Brahma and the other demigods were afraid of this unique, terrifying sound and Hiranyakasipu himself began to search out its source. Then, in order to prove correct the words of both his devotee Prahlada and Lord Brahma, the Supreme Lord appeared in a wonderful half-human and half-lion form called Nrisimha. Even though the Lord appeared before his very eyes, Hiranyakasipu still could not understand Him as the Lord; he saw Him as a strange creature. Without pure devotional eyes, one cannot see the Lord.
The terrible form of Lord Nrisimha is described in the Bhagavatam as follows: Both His eyes were full of anger and shining like molten gold, and His angry face was full of matted hairs and mane. He had terrible teeth, a sharp tongue like a razor’s edge, stretched eyebrows and raised ears, with a mouth and nose like the caves of a mountain. He had terrible divided jaws, His body was touching the sky, His neck was thick and short, His thighs and chest were broad and His stomach was thin. His body was covered with white hair and He had hundreds of arms and nails. Even though Hiranyakasipu understood this unique Nrisimha Deity to be the cause of his death, he became ready to fight and struck the body of the Lord with his mace. Lord Nrisimhadeva play-acted the battle for some time and then, neither in the daytime nor at night but at dusk, neither inside the house nor outside but on the threshold, neither in the sky nor on the ground but on His lap, and without any weapon but His nails, He tore open Hiranyakasipu’s chest and wore his intestines as a garland. The Lord also killed thousands of other demons with just His nails. After this, Lord Nrisimhadeva exhibited the triumphant behaviour of a conqueror. He left Hiranyakasipu and sat on the throne in the middle of the royal assembly in His angry form. Witnessing this terrible form of the Lord, no one could gather the courage to approach and serve Him, even though they were all ecstatic due to the demise of the cruel king. Brahma, Rudra, Indra, the Rshis, Vidyadharas, Nagas, Manus, Prajapatis, Gandharvas, Caranas, Yakshas, Kimpurushas, Vaitalikas, Kinnaras, Vishnu-parshadas and others, all prayed to Lord Nrisimha from a distance.
Although Brahma prayed to Lakshmi to go to Sri Nrisimhadeva to allay His anger, She could not go before this terrible never-before-seen Deity. Then Brahma asked Prahlada to go and pacify the anger of Nrisimhadeva. The reason for this was that this terrible and angry form of the Lord had appeared only due to the torture of bhakta Prahlada. Prahlada made obeisances to Sri Lakshmi, Brahma and the other demigods. Then he went to Nrisimhadeva and fell down at His lotus feet. Nrisimhadeva, being in the mood of parental affection, put his lotus hand on Prahlada’s forehead so that all of Prahlada’s defects, which were due to having been born in a demon dynasty, were removed. Transcendental knowledge was revealed in his heart and, overwhelmed with ecstatic devotion, he began to offer prayers to Sri Nrisimhadeva.
Satiated by the prayers of Prahlada, Nrisimhadeva wished to grant a boon to him, but Prahlada had no desire of taking any boon. The reason is that the person who serves the Lord with the desire for worldly pleasures or for the Lord’s blessings to get worldly benefit is not an actual servitor but a trader. Then Nrisimhadeva said that if He did not give Prahlada a boon, His designation as Varadarshabha, the Supreme Conferrer of boons, would be defamed. So Prahlada replied, “O Lord, if You wish to grant me a boon, please grant me the boon that there may not be any desire in my heart to ask a boon from You.”
Nrisimhadeva replied, “This cannot be accepted as your prayer for a boon because you have deceived Me.”
Prahlada then submitted this prayer to Nrisimhadeva: “My father struck Your holy body with his mace and he behaved maliciously with me because I worship You. Kindly purify him.”
Nrisimhadeva said to Prahlada, “Your father has seen Me and received My touch. Did this not purify him? O Prahlada, do you think the dynasty in which you have taken birth is still impure? Along with you, twenty-one of your ancestral generations have become purified.”

trih-saptabhih pita putah pitribhih saha te ’nagha
yat sadho ’sya kule jato bhavan vai kula-pavanah
(Srimad-Bhagavatam 7.10.18) “O sinless one, O sadhu, Your father has become pure along with twenty-one forefathers. The reason for this is that having taken birth in their dynasty, you have become the purifier of that dynasty.”

Sri Nrisimhadeva has two dispositions. He is terrible with non-devotees, but with devotees, He is very affectionate and caring. The following verse from the agamas is quoted as evidence by Sridhara Svami in his commentary on Srimad-Bhagavatam 7.9.1:

ugro ’py anugra evayam sva-bhaktanam nri-kesari
kesariva sva-potanam anyesham ugra-vikramah
(Caitanya-caritamrita, Madhya 8.6) “Although very ferocious, the lioness is very kind to her cubs. Similarly, although very ferocious to non-devotees like Hiranyakasipu, Lord Nrisimhadeva is very affectionate and kind to devotees like Prahlada Maharaja.”
(Bhaktivinoda Thakura)

This expresses thoroughly the glories of Sri Nrisimhadeva’s unique mercy. Devotion to Nrisimhadeva enhances bhakti and destroys uncongenial adverse motivations. The meaning of the word Hiranyakasipu is --- hiranya: gold or money, kasipu: bed, i.e. desire for money and women. The desire for name and fame also goes together with them. These are obstructions to devotion. Nrisimhadeva destroys the anti-devotional feelings of the Hiranyakasipu-like mentality of the living beings and nourishes the devotional attitude like that of Prahlada.
So, the favour of Bhakti-vighna-vinasana Sri Nrisimhadeva (Nrisimhadeva, the destroyer of hindrances to bhakti) is very necessary for neophyte devotees who have the weakness of non-eternal propensities.
The next two verses were composed by Sridhara Svami in his commentary on Srimad-Bhagavatam 1.1.1 and 10.87.1 respectively:

prahlada-hridayahladam bhaktavidya-vidaranam
sarad-indu-rucim vande parindra-vadanam harim “Let me offer my obeisances unto the Supreme lion-faced Lord Sri Hari who is residing within the heart of Prahlada Maharaja as condensed bliss, and who always removes nescience. His effulgence is like autumnal moonshine.”vag-isa yasya vadane lakshmir yasya ca vakshasi
yasyaste hridaye samvit tam nrisimham aham bhaje
“On whose lips Sarasvati (the goddess of learning) dances, on whose chest Lakshmidevi resides in the form of a golden line and whose heart is the abode of grand refulgence of the opulence of Absolute Knowledge-I offer my obeisances unto that very object of worship, Sri Nrisimhadeva.” ito nrisimhah parato nrisimho yato yato yami tato nrisimhah
bahir nrisimho hridaye nrisimho nrisimham adim saranam prapadye
(Nrisimha Purana, quoted in Caitanya-caritamrita, Antya 16.53)
“Lord Nrisimha is on this side and Lord Nrisimha is on that side. Wherever I go, Nrisimha is there. Nrisimha is outside and Nrisimha is also in my heart. I take shelter of that first appearance of Sri Nrisimha.”namas te nara-simhaya prahladahlada-dayine
hiranyakasipor vakshah-sila-tanka-nakhalaye
(Nrisimha Purana, quoted in Caitanya-caritamrita, Antya 16.52)
“I offer my respectful obeisances unto Lord Nrisimha who is the giver of bliss to Prahlada, and who possesses nails to tear the stone-like chest of Hiranyakasipu.” tava kara-kamala-vare nakham adbhuta-sringam
dalita-hiranyakasipu-tanu-bhringam
kesava dhrita-narahari-rupa jaya jagadisa hare
(Sri Jayadeva’s Dasavatara-stotra, 4th Verse)
“O Kesava! O Lord Hari, You have assumed the form of half-man and half-lion! The lotus flower is very soft, but Your most beautiful lotus-like nails are astonishing. The body of the mountain peak-like demon, Hiranyakasipu, has been ripped apart by them because they are also so hard. O Lord of the universe! All glories unto You!”

Regarding this subject, it is written in the Harivamsa Purana as follows: In Satya-yuga, Hiranyakasipu, the ancestor of the demons, was engaged in severe penances and demanded the boon from Brahma that he would not be killed by any demigods, demons, Gandharvas, serpents, Rakshasas or men. He asked that sages would not be able to curse him, that weapons, mountains, trees, wet or dry things would not be able to destroy him, that he would not die in heaven or on any other planet, either in the daytime or at night. Brahma granted him these boons saying, “So be it!” By achieving these boons, Hiranyakasipu became very excited. He became the ruler of heaven and began to torture and abuse the demigods in various ways. Unable to bear this torture, the demigods went to take shelter of Lord Vishnu, who, giving them assurance of protection said, “I am very soon going to destroy that demon who is proud of his boon, along with all his followers.” Bidding farewell to the demigods, Lord Vishnu began to consider how He would kill Hiranyakasipu and went off to the Himalayas. At last, He decided that He would assume the form of Nrisimha who would terrify all the demons (Daityas, Danavas and Rakshasas). He then assumed the form of half-man and half-lion. His luster began to rob the sun of its radiance. In this form, Lord Vishnu gradually approached the place where the demon king, Hiranyakasipu, was sitting in an excellent assembly accompanied by the demigods, Gandharvas and Apsaras (celestial nymphs) who were playing music with perfect rhythm. Being present in that assembly, the Lord looked at Hiranyakasipu again and again. At that time, Hiranyakasipu’s son Prahlada saw that Divine Form for a moment with spiritual vision, and addressed the demon king as follows: “O King, you are the chief of the demons. On seeing this Divine Form, it appears as though this is an inexpressible, divine influencing personality. Our demoniac dynasty will be destroyed by it. All immovable and moveable objects seem to exist in the body of this great person. He is some special personality.”
Hearing Prahlada’s statement, the demon king ordered his demon followers, “Kill this Lion immediately!” The demons attacked the Lion with all their might but they were soon destroyed along with their retinue. Nrisimhadeva then opened His mouth. His terrible roaring appeared like the sound of annihilation, and He easily destroyed the entire demon assembly. Then Hiranyakasipu himself began to shower dreadful weapons on Him. Both began a terrible fight.
The demons attacked Lord Vishnu, but they themselves were killed by Him. Ablaze with anger, Hiranyakasipu appeared to burn everything with his bloodshot eyes. The earth began to shiver, the oceans became perturbed and all the forests and mountains became restless. There was darkness everywhere; nothing was visible. Terrible disturbances took place and fearful winds began to blow. The symptoms of universal annihilation began to appear. Being lusterless and dark, the sun began to emit terrible smoke. Even the seven suns assumed forms of darkness and rose in the sky. Meteors fell in quick succession from the heavens.
Greatly enraged, Hiranyakasipu bit his lips with his teeth and ran to fight, taking his mace in hand. Upon seeing this, all the demigods became frightened. They went to Nrisimhadeva and said, “O Lord, destroy this wicked Hiranyakasipu with his followers. There is no one in this world who can kill him. Therefore, O Lord, kindly kill him for the benefit of the world and establish peace in all the three worlds.”
Hearing the prayer of the demigods, Nrisimhadeva began to make grave sounds. He leapt up and tore out the heart of the demon with his sharp nails and knocked him down on the battleground. When the horrible enemy-the demon king, fell down dead on the ground, all the people of the earth, moon, sun, planets, stars, rivers and mountains-one and all, were pleased. The demigods unitedly began to recite hymns to propitiate Nrisimhadeva. Celestial nymphs began to dance and sing. After the dancing and singing had ended, the Supreme Lord Narayana, who wears the symbol of Garuda on His flag, gave up His form of Nrisimha and assumed His own form. He then stepped onto an eight-wheeled excellently illuminated chariot, and set out for His place on the northern shore of the Ocean of Milk. In this way, Nrisimhadeva destroyed the demon, Hiranyakasipu.

The Glories of Observing Sri Nrisimha-caturdasi-vrata

vaisakhasya caturdasyam suklayam sri nrikesari
jatas tad asyam tatpujot-savam kurvita savratam
(Padma Purana) “Sri Nrisimhadeva appeared on the fourteenth lunar day (Caturdasi-tithi) of the bright fortnight of the month of Vaisakha. So, on this day, it is proper to worship and celebrate the appearance of Nrisimhadeva by following the rules of fasting and others.”prahlada-klesa nasaya ya hi punya caturdasi
pujayet tatra yatnenahareh prahladam agratah
(from the agamas)
“It is proper to first worship Prahlada before worshipping Nrisimha because the holy fourteenth lunar day of the bright fortnight has appeared in order to remove the distress of Prahlada.”

It is written in the Brihan-narasimha Purana as follows: Prahlada Maharaja desired to know from Sri Nrisimhadeva how he had developed devotion to His lotus feet. Nrisimhadeva replied, “In ancient times, there lived a brahmana named Vasu Sarma in the city of Avanti, who was well-versed in the Vedas. His good wife Susila was famous throughout the three worlds for her virtuous conduct and ideal devotion to her husband. Vasu Sarma fathered five sons in Susila’s womb. His first four sons were learned persons of good conduct and devoted to their father. But you, the youngest son, became attracted to a prostitute and lost your character. You were then known as Vasudeva. Your virtuous conduct was destroyed in the company of that prostitute. Due to a quarrel with the prostitute, on the Nrisimha-caturdasi-tithi both of you stayed awake throughout the night and unknowingly observed a fast. Therefore, both of you obtained the fruits of observing Nrisimha-caturdasi-vrata. The prostitute enjoyed as an Apsara in various ways in heaven and then became My favourite. As the son of Hiranyakasipu, you also took birth as My dear devotee. By observing this fast, Brahma has obtained the power of creation and Mahesvara has obtained the power of destruction of the three worlds. Other people also achieve all kinds of power and perform observance of this vow to fulfil all their desired objectives.” In his Laghu-bhagavatamrita, Srila Rupa Gosvami has written about the pre-eminence of the Lord’s appearance as Sri Nrisimhadeva, quoting the following reference from Sri Padma Purana:

nrisimha-rama-krishneshu sad-gunyam paripuritam
paravasthas tu te tasya dipad utpanna-dipa-vat
(Padma Purana) “Nrisimha, Rama and Krishna possess the pre-eminent presence of the totality of sixty attributes. Just as one lamp lights other lamps and then all lamps follow the same nature, similarly, although Rama and Nrisimha are manifested forms from the Prime Supreme Lord Sri Krishna, all three hold the supreme position with sixty attributes.”

Footnotes

[1]A well without water is known as a dark well. No man goes to such a waterless well, for if someone falls into that well, his rescue is very unlikely. Similarly, the house in which sadhus are not received cordially and in which, being deprived of the association of sadhus, the residents are engaged in sense enjoyment, is like a dark well. There is no possibility of rescue for the residents of such a house. Therefore, such a place of downfall of the corporeal soul (like falling into a dark well) is to be abandoned. [2]The qualities of a guru:

tad-vijnanartham sa gurum evabhigacchet
samit-panih shrotriyam brahma-nishöham
(Munòaka Upanishad 1.2.12) “To learn transcendental subject matter, one must humbly approach, with firewood in hand, a spiritual master who is learned in the Vedas and firmly devoted to the Absolute Truth.”tasmad gurum prapadyeta jijnasuh shreya uttamam
shabde pare ca nishnatam brahmany upashamashrayam
(Srimad-Bhagavatam 11.3.21)
“Therefore, anyone who seriously desires real happiness must seek a bona fide spiritual master and take shelter of him by initiation. The qualification of the bona fide guru is that he has realised the conclusions of the scriptures by deliberation and is able to convince others of these conclusions. Such great personalities who have taken shelter of the Supreme Lord, leaving aside all material considerations, should be understood to be bona fide spiritual masters.”

[3] Srotriya has two interpretations: (1) well-versed in the Vedas, and (2) ontological divine knowledge received through the preceptorial channel. [4] Grihavrata: One who moves around the house or property, i.e., one who engages his sense organs and energy for the sake of material property and consequently becomes attached to it.
However, saints also remain in a house, so it is said that the house also signifies the wife and material life. One who moves around the wife or family, or engages the senses and energy for them, is considered a grihavrata.
The real self is the atma (soul), so the gross and subtle bodies are also like houses. One who devotes his energy for the gross and subtle bodies is also a grihavrata.
Since all grihavratas are embodied souls, by the unrestricted use of the sense organs they will all enter into nescience and into the inferno of material life. Six billion such enslaved corporeal souls of the world cannot rescue even a single person from the shackles of worldly bondage. A perfect emancipated realised soul can rescue the whole world or universe --- but such realised souls are very rare. If one wants quality, one must sacrifice quantity. It is impossible to get both at the same time.
---from "Dasavatara - The Ten Manifestations of God"